Vertical axis wind turbine

Abstract

A Darrieus-type vertical axis wind turbine is disclosed which includes a vertically extending hollow rotor shaft mounted on a support structure with two, three, or four rotor blades of troposkein configuration on the rotor shaft for rotating the shaft in response to wind energy and thereby drive a generator to produce electrical power. The turbine includes an erection hinge and gin pole which permits the turbine to be cable hoisted using a simple winch mounted at or near ground level. The erection hinge and pole also permits the turbine to be completely assembled near ground level. The turbine includes two sets of guy cables. The upper set holds the upper bearing assembly and the upper rotor shaft portion in a fixed vertical position. The lower cable set holds the lower rotor shaft portion and the support structure also in a fixed vertical position. A flexible coupling is used to connect the low speed shaft of the generator speed reducer to the rotor shaft. This flexible low speed coupling greatly reduces wind induced torque ripple and related vibration and resonance problems. A guy cable tension adjustment and vibration damping apparatus is also disclosed.

I claim: 
     
       1. A vertical axis wind turbine comprising; a rotor shaft in an overlapping stacked assembly, said overlapping stacked assembly including an upper rotor bearing assembly overlapping the upper end of said rotor shaft with a rotor lower bearing and a central support structure overlapping the lower end of said rotor shaft, said central support structure having a hinge connection to a ground embedded central support structure anchor, said central support structure also including an erection gin pole and a hold down gin pole, said upper rotor bearing assembly is attached to four guy cable anchors by four upper bearing assembly guy cables, said central support structure is attached to an additional four guy cable anchors by four central support structure guy cables, said rotor shaft having attached a wind responsive means causing said rotor shaft to rotate in response to wind energy. 
     
     
       2. The vertical axis wind turbine of claim 1 wherein said hold down gin pole further includes a cable guide means. 
     
     
       3. The vertical axis wind turbine of claim 1 further including a substantially square guy cable anchor outline defined by said upper bearing assembly guy cable anchors embedded in the ground to mark the corners of the outline, with said central support structure anchor in the center of the square outline, with two imaginary lines drawn between opposite corners of the square anchor outline, a central support structure hinge connection pin axis making substantially a 45 degree angle with the square anchor outline opposite corner lines when projected onto the ground. 
     
     
       4. A method of assembling and erecting a vertical axis wind turbine comprising the steps of; providing a ground embedded central support structure anchor and eight ground embedded guy cable anchors; assembling a hinge connection between a central support structure and said central support structure anchor with said central support structure in a substantially horizontal position; assembling an overlapping stacked assembly in a substantially horizontal position; said overlapping stacked assembly comprising said central support structure overlapping the lower end of a rotor shaft through a rotor lower bearing, an upper rotor bearing assembly overlapping the upper end of said rotor shaft; providing an erection gin pole and a hold down gin pole attached to said central support structure; attaching one upper bearing guy cable between said upper rotor bearing assembly and a footing attached erection winch, strung in tension over said erection gin pole, to define a temporary erection winch cable, to both hold together and erection pivot said overlapping stacked assembly; assembling and attaching at least two rotor blades to said rotor shaft; attaching an additional upper bearing guy cable between said upper rotor bearing assembly and said central support structure in tension and strung over said hold down gin pole to hold said overlapping stacked assembly together; pulling said temporary erection winch cable to pivot said overlapping stacked assembly about said hinge connection to a vertical position.